Shock absorbing structure

ABSTRACT

For use with an upright abutment, a belt at its ends is mounted on the abutment and has its intermediate portion disposed with the belt web vertical and cantilevered out from and spaced away from the abutment. Frangible energy absorbers are disposed between the belt and the abutment and are supported thereon. Vertical cleats reinforce the belt web. In large installations, vertical diaphragm walls of belts are used adjacent energy absorbers. Anchor cables may pass through and engage the diaphragms or belts.

Elite States Patent [1 1 Walker et a1. Oct. 30, 1973 [54] SHOCKABSORBING STRUCTURE 1,132,315 3/1915 Evans 104/254 [75] Inventors: GrantW. Walker; Duane B. Ford; Lester Meinlel', of 1,503,049 7 1924 Jezek293/010. 5

Sacramento; Reid S. Larsen, Fair Oaks, all of Calif. FOREIGN PATENTS ORAPPLICATIONS 73 Assigneez Dynamics Research and 446,174 6/1927 Germany m293/55 B Manufacturing, inc. Sacramento7 532,304 1/1941 Great Britain114/219 Calif.

Primary Examiner-Dennis L. Taylor [22] Filed 1972 AttorneyMarcus Lothropet a1. 21 Appl. No.: 239,809

Related US. Application Data [57] ABSTRACT For use with an uprightabutment, a belt at its ends is mounted on the abutment and has itsintermediate portion disposed with the belt web vertical andcantilevered out from and spaced away from the abutment. Frangibleenergy absorbers are disposed between the belt and the abutment and aresupported thereon. Vertical cleats reinforce the belt web. in largeinstallations, vertical diaphragm walls of belts are used adjacentenergy absorbers. Anchor cables may pass through and engage thediaphragms or belts.

3 Claims, 6 Drawing Figures [62] Division of Ser. No. 69,872, Sept. 4,1970, Pat. No.

[52] 11.8. CI. 256/1, 256/l3.1 [51] Int. Cl. E01f 15/00 [58] Field oiSearch 256/1, 13.1; 114/219; 104/254, 256; 267/139, 140, 141, 1. 31119,-.5

[56] References Cited UNITED STATES PATENTS 3,614,148 10/1971 Favary267/139 Patented Oct. 30, 1973 2 Sheets-Sheet 1 Patented Oct. 30, 1973 2Sheets-Sheet H SHOCK ABSORBING STRUCTURE This is a division ofapplication Ser. No. 69,872, filed Sept. 4, 1970, now U.S. Pat. No.3,695,583.

It is becoming increasingly necessary to protect stationary structuresalongside vehicular ways or highways not only for the safety of thestructural elements themselves but likewise for the safety of thevehicles and their occupants in the event of collisions. In these and inother similar installations, the need is for an energy absorbinginstallation which is highly effective to absorb or dissipate the forcesinvolved in an impact and to be relatively inexpensive. It is importantthat the arrangement can easily be installed in the first instance andcan be replaced whenever necessary without undue labor or cost.Furthermore, the materials of the shock absorbing structure must inthemselves be relatively safe and harmless and in responding to animpact must not compound the difficulty.

It is therefore an object of the invention to provide a shock absorbingstructure, which can economically and simply be made and installed on anabutment and which can readily be maintained and replaced whennecessary.

Another object of the invention is to provide a shock absorbingstructure in which the materials involved are for the most partfrangible and do not cause any additional hazard upon impact.

Another object of the invention is to provide a shock absorbingstructure which in many instances will simply act as a fender or as abuffer to cause a carom or rebound of an impacting vehicle.

Another object of the invention is to provide a shock absorbingstructure that can withstand the customary environment, both freezingand high temperature, and which does not require any particularmaintenance over long periods of time unless impacted.

Another object of the invention is in general to improve shock absorbingdevices.

Other objects together with the foregoing are attained in theembodiments of the invention described in the accompanying descriptionand illustrated in the accompanying drawings, in which:

FIG. 1 is a cross section on a generally horizontal plane through anabutment provided with a shock absorbing structure in one form accordingto the invention;

FIG. 2 is a side elevation of the arrangement of FIG. 1, a portion beingbroken away to illustrate the interior in the cross section, thatsection being on a plane indicated by the line 22 of FIG. 1;

FIG. 3 is a cross section to an enlarged scale, the plane of sectionbeing indicated by the line 3-3 of FIG. 2;

FIG. 4 is a view comparable to a portion of FIG. 1 but showing amodified version of a cleated belt included in the invention;

FIG. 5 is a plan and cross section ofa device comparable to that of FIG.1 but showing a shock absorbing structure for installation with anenlarged abutment and under severer conditions than that of FIG. 1;

FIG. 6 is a side elevation of the structure disclosed in FIG. 5.

While it is recognized that the shock absorbing structure pursuant tothe invention can be embodied in various different environments; forexample, in docks, alongside buildings, in parking lots, for railroaduse and otherwise, it is particularly applicable to an installationalongside of or in connection with a vehicular highway from or alongsideof which there is provided an upstanding abutment 6. In FIGS. 1 and 2,this takes the form of a cylindrical column and can be considered to bemade of concrete such as a reinforced concrete pillar or highwaysupport.

Pursuant to the invention, there is provided a shock absorbing structureto take care of possible impacts against the abutment 6 from manydirections but particularly from the direction indicated by the arrow 7.For this purpose there is provided, as part of the shock absorbingstructure, a belt 8. This conveniently is a woven fabric belt or can bea composite structure; for example, made up of several layers such asfour layers of a polypropylene cloth with the layers, if not otherwisesecured, adhesively attached to each other by impregnation with apolyester resin. To this belt 8 there is preferably attached a pluralityof cleats 9 conveniently of a plastic material or alternatively of wood,fiber glass or light metal. The cleats have a generally semi-ovoid shapeand are secured in position in any convenient way; for example, by alayer 11 of glue or other adhesive or, in some cases, by bolts or rivetsalthough the adhesive construction is presently preferred.

While the cleats 9 can be dispensed with entirely for very light serviceor can be applied on but one side of the belt, they are preferablyapplied on the opposite sides of the belt. The cleats 12 on one side ofthe belt are arranged, preferably, directly opposite the cleats 9 on theother side of the belt and are similarly fabricated and secured inposition.

Either with or without the cleats, the belt 8 is secured at its oppositeends 13 and 14 to the abutment 6 by an appropriate fastening means 16and is arranged with the belt web disposed vertically. That is explainedby indicating that the belt thickness is relatively small or thinwhereas the belt width, that is, the width of the belt web is relativelygreat with respect to its thickness so that when the belt is disposed inposition, as shown, its web or width extends in a generally verticaldirection. The belt in this position continues to be fairly flexibleagainst a horizontal force but is relatively stiff or rigid against avertical force. The intermediate portion 17 of the belt is trainedaround the abutment 6 and is spaced therefrom to leave an interveningspace 18. The belt tends to cantilever out from its fastenings 16 and isgenerally self-supporting, although not necessarily of a definite shapewhen viewed in plan. The vertical strength is greatly augmented by thecleats 9 and 12, although the cleats, being spaced apart somewhat do notmaterially interfere with the general flexibility of the belt againsthorizontal impact.

Disposed in the space 18 between the abutment 6 and the intermediateportion 17 of the belt web are energy absorbing structures 19substantially as shown in the copending application of Grant W. Walkeret al., entitled Energy Absorbing Device," filed May 25, 1970 with Ser.No. 40,220. These energy absorbing structures are arranged at somedistance above the ground with one end of an energy absorbing deviceagainst the cleats 12 or directly against the belt web and the other endagainst the abutment 6. Often, friction alone is sufficient to hold theenergy absorbers in place, although they can be fastened to the abutmentor the belt web or both but in any case are supported by the abutmentand belt web. In some instances, some of the energy absorbers 2! are notcircular cylindrical as indicated in one location in FIG. 1, but are ofa truncated, conical shape as shown in another location in FIG. 1,although otherwise they are substantially the same as disclosed in thementioned copending application.

In a typical example, four such energy absorbing devices are arrangedwith their axes substantially horizontal and radial to the abutment 6and the belt 8 is relatively taut when the installation is completed.Usually the belt is spaced some distance above the ground preferably atabout the height of an automobile bumper or a major automobile bodyportion.

In operation, when a vehicle approaching in the direction of the arrow 7hits the shock absorbing structure the intermediate portion 17 of thebelt is somewhat deflected and flexed and if the impact is relativelylight and within the resiliency of the absorbers 19, very often nothingadditional occurs. On the other hand, if the impact is severe then thebelt yields and permits the frangible energy absorbers 19, 21 and thelike to crush and transform the impact energy so that the vehicle isslowed or stopped and the abutment 6 is saved.

A similar situation transpires when the impact is not directly in thedirection of the arrow 7 but rather is at another radial direction withrespect to the abutment 6 or is a glancing blow to the belt itself. Inthis instance, the belt also can yield or flex and the cleats themselvesassist in transmitting the force to the other parts of the structurewith results as previously described. In cases wherein the abutment 6might be struck from any direction, such as the base of a light standardin a parking lot, the construction, instead of being approximatelysemi-circular in plan, as seen in FIG. 1, can be circular around theabutment.

In some instances, as shown in FIG. 4, it is preferred to make thecleats other than of a semi-ovoid shape. Instead they are made so thatat their leading edges 26 they are relatively close to the belt, whereasat their trailing edges 27 they are relatively far from the belt whenconsidered in the immediate direction of approach of a vehicle such asis indicated by the arrows 28 and 29. In this instance also, just forillustration, the cleats are installed in pairs on the belt 31 and thecleats 32 and 33 are held in place by through rivets 34. This cleatshape tends to keep the cleats from being torn off the belt and tends toprevent entanglement with projecting parts of a vehicle sliding alongthe belt or giving it a glancing blow.

Under some conditions much greater resistance to impact and much greatershock absorbing capacity is requisite. If'the traffic is appropriatelychanneled, the shock absorbing structure itself takes on a directionalcharacteristic. As shown particularly in FIGS. and 6, an abutment 4! isprovided with a belt 42 secured thereto at its ends by fastenings 43.The intermediate portion 44 of the belt extends a substantial distanceahead of the abutment 41, the direction of potential impact on which isgenerally indicated by the arrow 45. In this instance the belt is spacedand supported substantially as before since there are horizontallydisposed energy absorbers d6 spaced above the ground and installed atdifferent locations.

There are also installed many other energy absorbers 47 in any selectedpattern. The numerous energy absorbers are preferably spaced apart andmaintained in position by intervening diaphragm walls 48 thatconveniently are curved substantially about the abutment 41. Thediaphragm walls can be thin sheets of suitable material or can be largesections of belt as shown in FIG. 1. In most cases, the diaphragms arepositioned and supported by a plurality of generally longitudinallyextending cables 51 and 52 that at one end are secured to the abutment41 and at the other end are connected by anchors 53 to the ground.

In the operation of this structure, an impact from head-on in thedirection of the arrow 45 acts substantially as previously describedsince the belt portion 44 tends to distribute the impact and itself toflex and give and yield in order that, if necessary, as many as possibleof the adjacent energy absorbers 46 and 47 will come into play totranslate the energy of the impacting device into crushing ordisintegration of the energy absorbers.

Very often in this type of installation, however, the impact is not headon from the direction of the arrow 45 but may very well be a glancingblow in the direction of an arrow 54 in which instance the belt tends toflex and yield in a lateral or transverse direction partly against thediaphragm walls 48 or belts and partly against the cables 51 and 52 withthe entire structure quite possibly yielding substantially in atransverse direction and if the impact is severe enough, permitting thebelt to yeild sufficiently so that the contained or surrounded energyabsorbers are fragmented. Particularly when belts are used asdiaphragms, the impact forces are distributed so that each transverserow of absorbers tends to disintegrate before the forces disintegratethe next row so that the absorbers remain in position relatively well upto the time it is their turn to disintegrate. High speed moving picturesof numerous impacts show this function clearly.

The exact shape of the shock absorbing structure can be varied from timeto time or from installation to installation depending upon the trafficconditions, the impact to be resisted or parried, the shape or nature ofthe abutment and various other factors; but in every instance, it hasbeen found beneficial to use a somewhat flexible belt arrangedvertically on edge and acting horizontally as a cantilever so that it isvirtually selfsupporting and forms a partial enclosure at least for anumber of energy absorbers disposed between the belt and the abutment.The maintenance or upkeep of the arrangement is relatively low and theoriginal installation is usually quite simple and economical. If animpact does shatter a number of the energy absorbers, they can readilybe replaced with the belt or belts being repositioned and in the FIGS. 5and 6 version with the cables themselves retightened if necessary. Inthe FIGS. 1 to 4 version, it is usually necessary only to replace someof the energy absorbers since the belt itself is not often badlydamaged, although if it is it can quite readily and economically bereplaced.

What is claimed is:

1. A shock absorbing structure for use with an abutment upstanding fromthe ground comprising a flexible belt including a relatively thinrelatively wide web, means for mounting the ends of said belt in apredetermined location relative to said abutment with the intermediateportion of said web extending from said abutment to a forward arearemote from said abutment and disposed with the width thereofsubstantially in a vertical plane and cantilevered horizontally awayfrom said abutment to leave an intervening space, a plurality ofvertically extending diaphragm walls disposed in said space and arrangedsuccessively one behind the other between said abutment and said forwardarea, and a plurality of horizontally extending, frangible energyabsorbing spacers disposed one behind the other in rows between saidbelt intermediate portion and said diaphragm walls and between saidsuccessive diaphragm walls and between said diaphragm walls and saidabutment.

1. A shock absorbing structure for use with an abutment upstanding fromthe ground comprising a flexible belt including a relatively thinrelatively wide web, means for mounting the ends of said belt in apredetermined location relative to said abutment with the intermediateportion of said web extending from said abutment to a forward arearemote from said abutment and disposed with the width thereofsubstantially in a vertical plane and cantilevered horizontally awayfrom said abutment to leave an intervening space, a plurality ofvertically extending diaphragm walls disposed in said space and arrangedsuccessively one behind the other between said abutment and said forwardarea, and a plurality of horizontally extending, frangible energyabsorbing spacers disposed one behind the other in rows between saidbelt intermediate portion and said diaphragm walls and between saidsuccessive diaphragm walls and between said diaphragm walls and saidabutment.
 2. A shock absorbing structure as in claim 1 in which saiddiaphragm walls are curved about said abutment.
 3. A shock absorbingstructure as in claim 1 in which substantially horizontal cables aresecured at their ends to said abutment and to the ground and betweentheir ends pass through said diaphragm walls in mutually supportingrelationship.